The tennis pro welcomed a baby girl on Friday — in the middle of the U.S. Open — at St. Mary’s Medical Center in West Palm Beach with fiancé Alexis Ohanian. “Tennis star Serena Williams gives birth to a baby girl weighing 6 pounds, 13 ounces. Mom and baby doing well,” WPBF-25 news producer Chris Shepherd announced on Twitter, citing a source at the hospital. (New York Daily News)